Over the past few years, dramatic increases in the cost of materials and labor have focused attention upon methods of reducing costs in various types of industrial and commercial devices. In the area of power transmission, it is usual that complex structures will be utilized to satisfy a relatively low torque transmission requirement. Recently industry has been concerned with production of transmission assemblies including utilization of stamped components. These structures, however, continue to be of complex construction including numerous components. Consequently, any malfunction within the device necessarily requires substantial time and possible expenditure of substantial sums toward replacement parts in putting the device back into an operable condition.
Change speed mechanisms currently used in bicycles are a specific area where the speed-changing device is of a complex nature. The usual three-speed, ten-speed, twelve speed, or eighteen speed shfting structure includes a plurality of sprockets in combination with a relatively sensitive shifting mechanism. The number of individual components in these devices is likewise substantial and repair necessarily involves expenditure of considerable time and money toward replacing a deflective component somewhere in the mechanism. A further disadvantage resides in the fact that these bicycle change speed devices can only be operated while the bicycle is in motion, thus preventing a change in a stopped or static condition.